9 research outputs found
The Effect of Reagents Mimicking Oxidative Stress on Fibrinogen Function
Fibrinogen is one of the plasma proteins most susceptible to oxidative modification. It has been suggested that modification of fibrinogen may cause thrombotic/bleeding complications associated with many pathophysiological states of organism. We exposed fibrinogen molecules to three different modification reagents—malondialdehyde, sodium hypochlorite, and peroxynitrite—that are presented to various degrees in different stages of oxidative stress. We studied the changes in fibrin network formation and platelet interactions with modified fibrinogens under flow conditions. The fastest modification of fibrinogen was caused by hypochlorite. Fibers from fibrinogen modified with either reagent were thinner in comparison with control fibers. We found that platelet dynamic adhesion was significantly lower on fibrinogen modified with malondialdehyde and significantly higher on fibrinogen modified either with hypochlorite or peroxynitrite reflecting different prothrombotic/antithrombotic properties of oxidatively modified fibrinogens. It seems that, in the complex reactions ongoing in living organisms at conditions of oxidation stress, hypochlorite modifies proteins (e.g., fibrinogen) faster and more preferentially than malondialdehyde. It suggests that the prothrombotic effects of prior fibrinogen modifications may outweigh the antithrombotic effect of malondialdehyde-modified fibrinogen in real living systems
Dynamic web pages
Serving dynamic web pages raises higher load of web servers and associated technologies. This can to some extent eliminate setting up reverse proxy with cache in front of the web server. The primary goal of this thesis is to implement this technique via presently most popular web server -- Apache. These Apache's proxy features were at first well tested and described, later practically applied in real LAMP software bundle enviroment (Linux, Apache, PHP, MySQL).Diplomová práce se zabĂ˝vá problematikou dynamicky zasĂlanĂ˝ch WWW stránek. Jejich pouĹľitĂ, hlavnÄ› u velmi zatĂĹľenĂ˝ch webovĂ˝ch aplikacĂ, pĹ™inášà kromÄ› nespornĂ˝ch vĂ˝hod pro uĹľivatele i nÄ›kterĂ© nevĂ˝hody z hlediska vĂ˝konu serverĹŻ a souvisejĂcĂch technologiĂ. K Ĺ™ešenĂ nÄ›kterĂ˝ch z nich lze vyuĹľĂt zpÄ›tnĂ˝ch proxy serverĹŻ. CĂlem bylo zprovoznit reverznĂ proxy server s meziukládánĂm v prostĹ™edĂ dnes nejpopulárnÄ›jšĂho webovĂ©ho serveru -- Apache. Tento pĹ™Ăstup je v práci nejprve podrobnÄ› popsán i otestován, následnÄ› je prověřen v praxi na vytĂĹľenĂ©m webovĂ©m sĂdle. ProstĹ™edĂm pro testovánĂ i realizaci praktickĂ© části byla populárnĂ platforma poskytovánĂ dynamicky generovanĂ˝ch internetovĂ˝ch stránek LAMP (Linux, Apache, PHP,MySQL)
Využità Topic Maps pro zlepšenà navigace na webu
CĂlem tĂ©to bakalářskĂ© práce je navrhnout a prototypovÄ› implementovat Ĺ™ešenĂ vyuĹľĂvajĂcĂ Topic Maps pro navigaci na webovĂ˝ch stránkách. JejĂm vĂ˝sledkem je pak aplikace postavená na spojenĂ tohoto relativnÄ› novĂ©ho mezinárodnĂho standardu pro organizovánĂ znalostĂ a populárnĂho Ĺ™ešenĂ poskytovánĂ webovĂ˝ch stránek softwarovou architekturou LAMP
Dynamic web pages
Serving dynamic web pages raises higher load of web servers and associated technologies. This can to some extent eliminate setting up reverse proxy with cache in front of the web server. The primary goal of this thesis is to implement this technique via presently most popular web server -- Apache. These Apache's proxy features were at first well tested and described, later practically applied in real LAMP software bundle enviroment (Linux, Apache, PHP, MySQL)
Využità Topic Maps pro zlepšenà navigace na webu
CĂlem tĂ©to bakalářskĂ© práce je navrhnout a prototypovÄ› implementovat Ĺ™ešenĂ vyuĹľĂvajĂcĂ Topic Maps pro navigaci na webovĂ˝ch stránkách. JejĂm vĂ˝sledkem je pak aplikace postavená na spojenĂ tohoto relativnÄ› novĂ©ho mezinárodnĂho standardu pro organizovánĂ znalostĂ a populárnĂho Ĺ™ešenĂ poskytovánĂ webovĂ˝ch stránek softwarovou architekturou LAMP
Plasma Levels of Aminothiols, Nitrite, Nitrate, and Malondialdehyde in Myelodysplastic Syndromes in the Context of Clinical Outcomes and as a Consequence of Iron Overload
The role of oxidative stress in the initiation and progression of myelodysplastic syndromes (MDS) as a consequence of iron overload remains unclear. In this study we have simultaneously quantified plasma low-molecular-weight aminothiols, malondialdehyde, nitrite, and nitrate and have studied their correlation with serum iron/ferritin levels, patient treatment (chelation therapy), and clinical outcomes. We found significantly elevated plasma levels of total, oxidized, and reduced forms of cysteine P<0.001, homocysteine P<0.001, and cysteinylglycine P<0.006 and significantly depressed levels of total and oxidized forms of glutathione P<0.03 and nitrite P<0.001 in MDS patients compared to healthy donors. Moreover, total (P=0.032) and oxidized cysteinylglycine (P=0.029) and nitrite (P=0.021) differed significantly between the analyzed MDS subgroups with different clinical classifications. Malondialdehyde levels in plasma correlated moderately with both serum ferritin levels (r=0.78, P=0.001) and serum free iron levels (r=0.60, P=0.001) and were significantly higher in patients with iron overload. The other analyzed compounds lacked correlation with iron overload (represented by serum iron/ferritin levels). For the first time our results have revealed significant differences in the concentrations of plasma aminothiols in MDS patients, when compared to healthy donors. We found no correlation of these parameters with iron overload and suggest the role of oxidative stress in the development of MDS disease
Linking aberrant glycosylation of plasma glycoproteins with progression of myelodysplastic syndromes: a study based on plasmonic biosensor and lectin array
Abstract Aberrant glycosylation of glycoproteins has been linked with various pathologies. Therefore, understanding the relationship between aberrant glycosylation patterns and the onset and progression of the disease is an important research goal that may provide insights into cancer diagnosis and new therapy development. In this study, we use a surface plasmon resonance imaging biosensor and a lectin array to investigate aberrant glycosylation patterns associated with oncohematological disease—myelodysplastic syndromes (MDS). In particular, we detected the interaction between the lectins and glycoproteins present in the blood plasma of patients (three MDS subgroups with different risks of progression to acute myeloid leukemia (AML) and AML patients) and healthy controls. The interaction with lectins from Aleuria aurantia (AAL) and Erythrina cristagalli was more pronounced for plasma samples of the MDS and AML patients, and there was a significant difference between the sensor response to the interaction of AAL with blood plasma from low and medium-risk MDS patients and healthy controls. Our data also suggest that progression from MDS to AML is accompanied by sialylation of glycoproteins and increased levels of truncated O-glycans and that the number of lectins that allow discriminating different stages of disease increases as the disease progresses